The present invention generally relates to fluid jet nozzles on downhole drilling bits and more particularly involves a retention system for locating and retaining a directed jet nozzle in a rolling cutter drill bit.
In the rolling cutter drill bit industry, there are generally several kinds of fluid-cooled rolling cutter bits. Two of the major types of bits are the regular fluid-cooled bit and the "jet" nozzle bit. The "jet" nozzle bit is the type utilizing one or more nozzles located in the bit body or the lugs of the bit to provide a relatively high-pressure, high-velocity flow of cooling and cleaning fluid into the borehole in the area in which the drill bit is cutting rock.
In a copending application, U.S. Ser. No. 241,909, filed Mar. 9, 1981, by Robert H. Slaughter for "Mounting Means for Drill Bit Directed Nozzles"; which application is assigned to the same assignee as is the present invention, which application is herein incorporated by reference, a jet nozzle rolling cutter drill bit is disclosed having directed nozzles oriented in a particularly advantageous position with respect to the rolling cutters. In the aforementioned copending application, it is disclosed how this particular orientation of the jet nozzles with respect to the rolling cutters provides a more efficient cutting action on the borehole and a more effective cleaning of the cutters to prevent balling and loss of cutter penetration into the formation. The aforementioned copending application, while providing a significant improvement over the prior art, suffers from one disadvantage in that the system of aligning the nozzles in their proper orientation with respect to the cutters, is relatively cumbersome and difficult to manufacture. Also, the alignment system therein is separate and distinct from the retention system and adds further expense to the manufacture of the bit.
In addition to the alignment system disclosed in said copending application, there is an alignment system disclosed in U.S. Pat. No. 3,084,751 dated Apr. 9, 1963 to W. E. Scarborough for a nozzle retention system in a common jet nozzle bit. The Scarborough bit does not utilize the directed nozzles, but merely discloses nozzles directed downward at the borehole face between the rolling cutters. Likewise, the Scarborough disclosure, while teaching the use of a deformable pin in coacting grooves between the nozzle and the body, has no means for aligning the nozzle with respect to the cutters since the Scarborough bit does not use oriented nozzles.
The present invention overcomes the disadvantages of the prior devices and provides a system which features both the retention and alignment of oriented nozzles in a rolling cutter bit.